PRACTICAL EXPERIENCE IN RE-ESTABLISHING CONTROL OVER SRBS AND BACTERIA GENERATED H_2S IN SUBSEA PIPELINES FOLLOWING HURRICANE IKE

摘要

Hurricane Ike crossed the Gulf of Mexico, with landfall at Galveston, Texas at 2:10 AM on September 13, 2008. As the hurricane was crossing the Gulf of Mexico, one of the major laterals in an offshore pipeline system was ripped from the central trunkline. As a consequence of that breach, approximately 75,000 BBL (11.9 MM Liters) of seawater entered the trunkline, and approximately 40,000 BBL (6.4 MM Liters) of seawater entered the lateral. Following repairs, the 30" (76.2 cm) trunkline was dewatered, and 90 ppm hydrogen sulfide (H_2S) was detected ahead of the pig in the trunkline. When the lateral was dewatered two months later, the dissolved H_2S spiked to 10,000 ppm. Since the normal gas production contained at most traces of H_2S, the hydrogen sulfide was attributed to microbiological activities that occurred after the seawater entered the pipelines. This report provides an overview of the pipeline repairs, the initiatives to dewater the pipelines, the biocide and hydrogen sulfide scavenger treatments, and the pigging program, which were implemented to re-establish control over SRBs and the H_2S they generated, thereby minimizing that threat to pipeline integrity.